Top wired electrical cap and connector



Sheets-Sheet 1 B- C. WEBSTER ET AL TOP WIRED ELECTRICAL CAP AND CONNECTOR Oct. 15, 1957 Filed Sept. 2, 1954 Oct. 15, 1957 B. c. WEBSTER ETAL TOP WIRED ELECTRICAL CAP AND CONNECTOR 2 Sheets-Sheet 2 Filed Sept. 2, 1954 ATTO RN EYS United States Patent This invention relates to a top wiredelectrical cap and connector, and has for an object to provide an improved construction for this type of device, including improved means for connecting the lead wires to the contacts in the electrical device, either the cap or the connector, which does not require the use of binding screws with their objections of requiring considerable time for making the connections, and their liability to loosening up in use, with consequent loss of proper electrical connec- "tionand danger 'of short circuits.

Another object is to provide a device of this character with improved means or strain relief clamps for clamping the insulating cord, which clamps are so constructed and arranged that operation of the screws in 'eifecting connection of the lead wires to the contacts in the device will also and at the same time clamp the cord clamps against the insulating cord or cable containing the conductor wires.

Another object is to provide means whereby when the screws for cifecting the clamping of the conductor wires to the electrical contacts in the device are released, the clamping elements are automatically separated to facilitate the insertion of the conductor wires to the clamping position.

Still another "object is to provide an improved device of this character including improved means of quickly andeliectively clamping and electrically connecting the conductor wires to the contacts in the device, and in which clamping of all of, the wires to the various contacts will be simultaneously effected with one operation.

A further object is to provide a device of this character including relatively movable elements for clamping the lead wires to the stationary contacts, in which these elements are always connected and do not have to be disconnected to make the wiring connections. 7

With the foregoing and other objects in view, we have devised the construction illustrated in the accompanying drawings forming a part of this specification. It "is, however, to be understood the invention is not limited to the specific details of construction and arrangement shown, but may embody various changes and modifications within the scope of the invention.

In these drawings:

Fig. 1 is a side elevationof an electrical cap or plug involving this invention, showing the cord clamps in the released position;

Fig. 2 is a top plan view thereof;

Fig. 3 is a vertical section substantially on line 3'3 of Fig. 2, showing the two members of the insulating body separated in the released position and the cord clamps also in the separated or released position;

Fig. 4 is a similar section showing the body members and the cord clamps in their clamping positions;

Fig. 5 is a partial side elevation with-a portion of the shell broken away and'shown in section, the plane of the section being substantially on line S -'5 of Fig. 2;

"Fig. 6 is a detail sectionsub'st'anti'ally on line 6-6 of Fig. 2;

ice

2 v Fig. 7 is a section substantially on line 7'-=7 of Fig. 2, showing the body members in the separated or released position and in a position to permit insertion of the conductor wires to the clamping position; I

Fig. 8 is a similar section showing the lead wires inserted and the body members brought to the clamping position;

Fig. 9 is a top plan view of the lower body member removed from the casing, but showing the cap contact blades in position;

Fig. 10 is a perspective view looking toward the top f the upper member of the body showing it removed from the casing or shell and also with the cord clamps removed;

Fi 11 is a bottom perspective view of the member of Fig. 10, but showing the connecting screws and separating springs in position, as well as one of the cord clamps;

Fig. 12 is a detail section substantially on line 12-42 of Fig. 9;

Fig. 13 is a perspective view 'of one of the contact blades, and

Fig. 14 is a perspective view of one of the cord clamps.

This invention is shown as applied to an attachment plug cap or electrical connector cap, but it is equally adaptable for use with a connector into which the blades of the cap may be inserted for effecting electrical connection between the two. This could be eifected by lengthening the lower member of the body to enclose the receptacle or connector contacts and provide its lower surface with entrance slots leading to these contacts for entrance of the contact blades of a cap.

The device shown comprises a body including two members which for more ready identification will be called an upper member 1 and a lower member 2. These members are of insulating material mounted in an enclosing protective shell or casing 3 of metal of suitable gauge or thickness, this shell or casing being provided with an inwardly directed flange 4 at its upper end seating against a shoulder 5 at the upper end of the body member 1 and at the outer side of extensions or boss portions 6 on the top of the body member. The body member 1 is a tight or forced fit in the shell or casing 3, and while the body member 2 has a close fit with this shell, it is also slidable longitudinally in the shell for a purpose presently to be described. Its lower body member 2 carries the stationary contacts in the device, in the device illustrated comprising the blade contacts 7 and 8 which project from the lower end wall or surface of the member 2 for insertion into the entrance slots in the connector type of device for engagement with the connector or receptacle contacts therein. These blade contacts may be the straight standard type of blade, or they may be widened at their free end portions to provide lateral inwardly facing shoulders 9, which by turning the cap with respect to the connector can be shifted behind locking shoulders within the connector for locking the two together, as, for example, in the type of locking cap and connector shown in Hubbell Patent No. 1,771,729, July 29, 1930, Interlocking Plug and Cap. By making the blades 7 and S of difierent widths or shapes, the cap can be a polarized cap.

The lower body member 2 is provided with recesses 19 extending downwardly from its upper wall andeach having a downwardly and outwardly inclined clamping surface ll. Each contact 7 and 8 is provided with a laterally inclined lug 12 at its upper end which seats on this surface, as indicated in Figs. 7 and 8, the body porlaterally extending lugs 15 and 16 adjacent lug 12, preferably curved and seating in correspondingly shaped grooves or channels 17 and 18 in the opposite side walls of the recesses 10, to rigidly hold these contacts in place with the inclined lug 12 resting on inclined surfaces 11 in these recesses. The contacts may be inserted by passing their lower ends downwardly from the top of the member 2 through these slots 14 with the lugs 13 and 16 sliding downwardly in the channels 17 and 18 until the inclined lugs 12 rest on the inclined surfaces 11. The blade contacts are preferably a tight fit. in these slots and openings so that they have to be forced into position and will not tend to shift upwardly in the member 2 when the body members are separated, as shown in Fig. 7.

The upper body member 1 has downwardly extending extensions or lugs 19 on its lower side substantially the width of the recesses and adapted to slide into these recesses, and each is provided with a downwardly and outwardly inclined clamping surface 20 opposite the clamping surfaces 11 on the lower member 2. The upper memher 1 is provided with a central passage 21 for insertion of lead or conductor wires 22 for engagement with the stationary contacts 7 and 8. These could be separate conductors but are preferably insulated conductors in an insulated cord or cable 23. In making the connections to the members 7 and 8, a part of the insulation of cord or cable 23 is removed from the conductors 22, and then the free ends of these conductors are stripped of their insulation, leaving bared or stripped ends 24, whcih may be inserted between the lugs 12 of the stationary contacts and the inclined clamping surfaces 20 of the upper body member 1, as indicated in Fig. 8, and then by drawing the two body members 1 and 2 together these bared ends of the conductors are firmly clamped against inclined lugs 12 of the stationary contacts, making a good tight connection between them and also a good efiective electrical connection between them. In efiect, therefore, the contact lug 12 and the bared end 24 of the conductor are firmly clamped together between the inclined surfaces 20 and 12 on the two body members 2 and 1. To improve the grip between the contact lug 12 and the conductor, the lug may be provided with some gripping means, that shown comprising a longitudinal slot 25 which is narrower than the diameter of the conductor so that the conductor can seat in this slot and be forced part way into it and firmly held and gripped by the opposite ends of the slot, and also the side edges of the slot will hold the conductor from shifting sideways. The free end of the lug 12 may be provided with a notch or recess 26 to help guide the free end of the conductor into its proper position on the top of the lug 12. Also, the member 1 may be provided with a transverse dividing wall 27 in the passage 21 adjacent its lower end to provide separate passages 21a for the conductors and to separate them as they are inserted in position. The upper ends of the passages 21a may be flared upwardly and outwardly, as shown, to further facilitate insertion of the conductor wires. The lower edge of this transverse partition wall may be tapered, or substantially V-shaped, as indicated at 28 in Figs. 7 and 8, to seat in a similarly shaped transverse groove or recess 29 between the recesses 16 in the lower member 2 when the two members are brought together.

Means is provided for connecting the two members 1 and 2 of the body and drawing them together or toward each other to clamp the conductor wires 24 against the lugs 12 of the stationary contacts, as above described. Specifically, the upper member 1 of the body is a tight forced fit in the shell 3, but the lower member 2 of the body, although a good fit in the shell, is slidable in this shell toward and from the member 1. The means for connecting the two members 1 and 2 and drawing the n together for the clamping operation comprises two screws 36 passing through openings 31 in the upper member 1 and threaded into inserts 32 molded in the lower member 2, as indicated in Figs.'3 and 4. Embracing each screw between the two body members 1 and 2 is a coil spring 33 normally compressed so as to tend to separate the two members 1 and 2, and in order to permit use of a longer spring the upper member 1 may be recessed, as indicated at 34, to receive the upper end of the spring.

Thus, when the screws 36 are loosened these springs 33 tend to shift the lower body member 2 downwardly and separate it from the upper member 1, as shown in Figs. 3 and '7, and thus separate the two clamping surfaces 11 and 2d, as shown in Fig. 7, to permit insertion the hated ends 24 of the conductors to a position on top of the inclined lugs 12 of the stationary contacts and between these lugs and the upper clamping surfaces 20, and then by operating screws 39 the two body members 1 and 2 may be drawn together, specifically the lower member 2 may be shifted or drawn upwardly toward the member 1, in one operation, firmly clamping the hatred ends 2% of the conductors by means of the surfaces 20 against the lugs 13 to make the securing and electrical connections between the conductors and the contacts. Although only a pair of contacts 7 and 8 are shown, it will be understood the same construction, arrangement and operation may be employed with a greater number of contacts, as three or four, for example.

Means is also provided for, at the same time, and with the same operation, clamping the insulated cord or cable 23 to the electrical device to relieve strains on this cord from the connections between the conductors and the stationary contacts. This clamping means or strain relief comprises two cord clamps 35, and each clamp, as shown in Fig. 14, comprises a transversely curved upper gripping portion 36 adapted to grip opposite sides of the cord 23, a lower transverse bar 37 having inwardly offset squared end lugs 38, and a curved intermediate connecting portion 39 having a longitudinal slot 40. The bar 37 and the end lugs 38 are seated in a recess 41 in the top of the body member 1, with one of these recesses located on diametrically opposite sides of this body, as indicated in Figs. 2 and 10, and the top wall of the body member 1 is also provided with a transverse channel or groove 42 extending between each recess 41 and the cord passage 21. The lower edges of the bar 37 and the pivot lugs 38 rest on the bottom of the recess 41 with the concave side of the gripping upper end 36 facing inwardly, and the lugs 38 are held in this recess by the overhanging flange 4 of the protector shell 3, as shown in Figs. 2 to 6 inclusive. The screws connecting the two body members 1 and 2 pass upwardly at the inner side of the notches 41 and extend through the slots in the two clamping members 35, so that their heads 43 are above the curved body portions 39 of the clamps, and to secure better bearing a washer 44 may be provided between these heads of the screws and the curved portions 39 of the clamps.

In operation, when the screws 30 are retracted or loosened to permit the body members 1 and 2 to separate to the positions of Figs. 3 and 7, the strain relief clamps 35 are also released so that they may be swung outwardly about the pivot lugs 38 to their released or separated positions, with their upper curved clamping portions 36 separated, as shown in Figs. 1 and 3. As they are shifted to this position, the flat upper and lower edges 45 and 46 will be shifted to a position parallel to or fiat on the inner or lower surface of the flange 4 of the shell and the bottom wall of the recess 41, as shown in Fig. 6, with a sort of click or snap action, the flange 4 being sufiiciently resilient and yielding to permit this action, the height of the lugs 38 and the distance between the bottom of the fiange 4 and the bottom of the recess providing a tight grip on the lugs, and this grip against the flat surfaces 45 and 46 will retain and hold the strain relief clamps 35 in this separated or open position, as shown in Fig. 3, while the cord 23 is inserted into the passage 21 between them, and the bared ends 24 of the conductor wires are inserted into the spaces between the tops of the inclined lugs 12 of the stationary contacts and the clamping walls 20 on the upper member 1. Then "asronlre V by operating screws 30the lower body member 2 is drawn upwardly "toward'the upper member 1'to clamp the bared ends 24 of the conductor wires against the inclined lugs 12 of the stationary contacts, and also to clamp these lugs and the bared wires between the two clamping walls 11 and 20, to provide a firm ,grip and excellent electrical contact between the conductor wires and the contacts. At the same time, thesescrews draw downwardly on the strain relief clamps 35 and shift them from their open separated position of Fig. 3 about their pivot lugs 38 to the clampingiposition of Fig. '4, shifting their upper curved clamping portions 35 against the opposite sidesof the insulated "cord :or cable 23 to firmly grip this cable and release strain on this cable from the clamped connection between the ends 24 and the lugs 12. It will also be seen from the arrangement of these clamps 35, as they move from the open or released .position .of Fig. 3 to the clampedcr closed position of Fig. 4, the curved clamping upper ends 36 move downwardly and inwardly, and as they engage and grip the cord 23 they tend to shift this cord downwardly and inwardly and retain the bared ends 24 of the conductors in their proper position on top of thelugs 1-2 of the contacts. In other words, this operation of the strain relief clamps 35 prevents any tendency of the cord 23 and the conductors 24 to .move upwardly out of position during the clamping operation on manipulation of the clamping screws .30, and insures that the cord and the conductors are held in the proper position during the final setting or clamping operation. Thus it will be seen that the single operation of :setting up the screws 30 not only clamps all of the conductor wires and makes the connections between the conductors and the stationary contacts of the device, but this operation at the same time operates the strain relief clamps 35 to set and clamp them against the conductor cord 23.

It will be seen from the above that this is a very simple construction and one that may be easily and quickly operated to not only make the electrical connection between the conductor wires and the stationary conductors in the device or fixture, but that with the same operation the strain relief clamps are clamped on or set against the insulated cord; also that the use of binding post screws for making individual connections between each conductor wire and its contact is eliminated, greatly facilitating the operation of connecting the conductor to the contact and eliminating the danger of these connections becoming loose in operation; that in making the connections between the conductors and the contacts the bared ends of the wires are merely inserted into the proper position with respect to the contacts, and then firmly and effectively clamped by merely setting up the two screws, eliminating any necessity of wrapping the bared ends of the wires around binding screws, which might be a difficult operation with relatively large gauge wires, and also eliminating the possibility of such screws becoming loosened in operation and causing a loosened connection. Also, on releasing of these clamping screws, the springs automatically separate the two body members preparatory to the insertion of the conductor wires and retain them in this position while the wires are being inserted, thus still further facilitating the operation of effecting the securing and electrical connections between the wires and the contacts. The units are always together and do not have to be separated to make the wiring connections. Polarization markings for the cap can be placed on top of bosses 6 if desired.

Having thus set forth the nature of our invention, we claim:

1. In an electrical device of the character described, a body comprising upper and lower members of insulating material, electrical contacts mounted in the lower memher, the upper member provided with means for passage of wires from aninsulating conductor cord to said contacts, said body members provided with opposed clamping surfaces for clamping the bared ends of the wires to the contacts to form an electrical connection between them, jcord clamps including pivotal means connecting them to the upper body member in position to be-clamped against opposite sides of a conductor cord -so connected, screws connecting the bodymembers and adaptedtodraw them together to clamp the wirestothecontacts, and said screws being also so connected to therespective clamps that operation of these screws to draw the body members together will also swing the clamps on theirpivots to clamp these-clamps against opposite sides of the'cord.

2. In an electrical device of the character described, a body consisting of an upper and a lower member only of insulating material, stationary contacts mounted in the lower member and each including an inclined lug at its vupper end, said lower member being provided with downwardly and outwardly inclined surfaces on which said lugs are seated, said upper member provided with downwardly and outwardly inclined clamping surfaces above said lugs, said upper member provided with a passage for insertion of the bared ends of conductor wires between said lugs and the clamping surfaces, and screws connecting said body members and drawing them together to-clamp said wires to the lugs by said surfaces.

3. In an electrical device of the character described, a body comprising upper and lower members of insulating material, said lower member having transverse recesses in its top -wall each having an inclined bottom surface and upright inwardly facing channels in its oppositeside walls, contacts mounted in said recesses each including aninclined lug at its upper end seated on the inclined surface and laterally extending lugs in said channels, the upper member having inclined clamping surfaces on its -lower side over said inclined lugs, said upper member having a passage wherebylead wires may be inserted with their bared ends between the inclined lugs and said clamping surfaces, and means for connecting and drawing the members together to clamp the lead wires against said lugs.

4. in an electrical device of the character described, a body comprising upper and lower members of insulating material, said lower =member having transverse recesses in its top wall each having an inclined bottom surface and upright inwardly facing channels in its opposite side walls, contacts mounted in said recesses each including an inclined lug at its upper end seated on the inclined surface and provided with a longitudinal slot, said contacts also including laterally extending lugs seated in said channels, the upper member provided with inclined clamping surfaces on its lower side over said inclined lugs and passages whereby conductor wires may be inserted with their bared ends on these lugs under said clamping surfaces, and means connecting said members and for drawing them together to clamp the wires against said inclined lugs and in the said slots.

5. In an electrical device of the character described, a body comprising upper and lower members of insulating'material, said lower member having transverse recesses in its top wall each having an inclined bottom surface and upright inwardly facing channels in its opposite side walls, contacts mounted in said recesses each including an inclined lug at its upper end seated on the inclined surface and laterally extending lugs in said channels, the upper member having inclined clamping surfaces on its lower side over said inclined lugs, said upper member having a passage whereby lead wires may be inserted with their bared ends between the inclined lugs and said clamping surfaces, screws connecting said body members and adapted to-draw them together to clamp the lead wires against said lugs, and compression springs between said members tending to separate them to shift the lower member away from the upper member when the screws are loosened.

6. In an electrical device of the character described, a body'comprising upper and lower members of insulating material, stationary electrical contacts mounted in the lower member each including a laterally extending lug at its upper end supported by said member, said upper member provided with clamping surfaces opposite said lugs and a passage for insertion of the bared ends of conductor wires to a position between said lugs and the clamping surfaces, screws connecting said body members and adapted to draw them together to clamp the conductor wires against the lugs by said clamping surfaces, and spring means on the screws between the body members biased to separate these members when the screws are loosened and permit insertion of the conductor wires to the clamping position between the lugs and clamping surfaces.

7. In an electrical device of the character described, a body comprising upper and lower members of insulating material, stationary electrical contacts mounted in the lower member each including a laterally extending lug at its upper end supported by said member, said upper member provided with clamping surfaces opposite said lugs and a passage for insertion of the conductor wires in an insulated conductor cord to a position between said lugs and the clamping surfaces, screws connecting said body members, and adapted to draw them together to clamp the conductor wires against the lugs by said clamping surfaces, cord clamps pivotally connected to the upper body member in position to be clamped against opposite sides of the conductor cord so inserted, and said screws being connected to said cord clamps and operative to clamp said clamps against the cord in the same action they draw the body members together to clamp the conductor wires to the stationary contacts.

8. In an electrical device of the character described, a body of insulating material, stationary electrical contacts mounted in the body, said body provided with means for passage of the conductor wires from an insulated conductor cord to said contacts, cord clamps pivotally connected to the body in position to be clamped against the opposite sides of said conductor cord, means for clamping the bared ends of the conductor wires to the contacts, screws in the body arranged to operate said clamping means to secure the wires to the contacts, and said screws connected to the cord clamps and operative to clamp said clamps against the conductor cord in the same operation of clamping said conductors to the contacts.

9. In an electrical device of the characterdescribed, a body of insulating material comprising upper and lower members movable toward and from each other, stationary contacts mounted in the lower member, said upper member having passage means for conductor wires from an insulating conductor cord to said contacts, means in the body for clamping the conductor wires to the contacts by relative movement of the members toward each other, cord clamps pivotally connected to the upper member in position to be clamped against the opposite sides of said conductor cord, screws connecting the body members and operative to draw them together to clamp the conductors to the contacts, and said screws connected to the cord clamps and operative to clamp these clamps against the cord in the same operation of clamping the conductors to the contacts.

10. In an electrical device of the character described, a body of insulating material comprising upper and lower members movable toward and from each other, stationary contacts mounted in the lower member, said upper member having passage means for conductor wires from an insulating conductor cord to said contacts, means in the body for clamping the conductor wires to the contacts by relative movement of the members toward each other, cord clamps pivotally connected to the upper member in position to be clamped against the opposite sides of said conductor cord, screws connecting the body members and operative to draw them together to clamp the conductors to the contacts, said screws connected to the cord clamps and operative to set these clamps against the cord in the same operation of clamping the conductors to the contacts, and spring means between the body members operative to separate these members when the screws are loosened to release the conductor wires and the cord clamps.

11. In an electrical device of the character described, a body of insulating material comprising upper and lower members movable toward and from each other, the lower member being provided with recesses in its top wall having inclined bottom walls and slots in its lower wall leading to said recesses, stationary contacts in said lower member including inclined laterally extending lugs at their upper ends supported on the said inclined bottom walls of said recesses and lateral lugs on its side edges seated in said slots together with contact blades projecting from said lower wall, said upper member having passage means for conductor wires to said contacts, downwardly extending lugs on the upper member having inclined surfaces for clamping the bared ends of the conductor wires to the inclined lugs at the upper ends of the contacts by movement of the body members toward each other, and screws connecting the body members and operative to draw them together to clamp the conductor wires to the contacts.

12. In an electrical device of the character described, a body of insulating material comprising upper and lower members movable toward and from each other, a metal shell enclosing said members and including a flange at its upper end extending over the upper end of the uppermember, stationary contacts mounted in the lower member, said upper member having passage means for conductor wires from an insulating conductor cord to said contacts, means in the body for clamping the conductor wires to the contacts by relative movement of the members toward each other, cord clamps including pivot lugs between said flange of the shell and the end of the body to pivotally connect the clamps to the body and including cord clamping portions on opposite sides of the passage means, said clamps also including intermediate portions between the clamping portions and the pivot lugs each provided with an elongated slot, headed screws passing through said slots and the upper body member and having screw thread connection with the lower body member, the heads of the screws being located at the upper sides of the cord clamps, and said screws operable to draw the body members together to clamp the conductor wires to the contacts and at the same time to shift the clamping portions of the clamps inwardly about their pivot lugs to clamp the Opposite sides of a conductor cord between them.

13. In an electrical device of the character described, a body member of insulating material, a metal shell enclosing the body member and including a flange at its upper end extending over the upper end of the body, stationary contacts in the body, said body having a passage through its upper end for conductor wires from an insulated conductor cord to said contacts, cord clamps each comprising a curved body portion having at one end laterally extending flat edged pivot lugs located between the flange and the end wall of the body and held against the body by said flange, said clamps including curved clamping portions at the other ends of their body portions to clamp an insulated conductor cord between them, said body portions of the clamps each provided with an elongated slot, and screws connected to the body and passing through said slots and having means at their upper ends above the clamps to swing these clamps about their pivot lugs and clamp a conductor cord between them.

References Cited in the file of this patent UNITED STATES PATENTS 1,876,876 Douglas Sept. 13, 1932 1,938,303 Tregoning Dec. 5, 1933 2,110,508 Klopfer Mar. 8, 1938 

